Cashman: Tanaka's woes warranting 'CSI: The Bronx' investigation

So perplexing are Masahiro Tanaka's struggles through the first couple months of the 2017 campaign that the New York Yankees have just about resorted to forensic science to identify the source of his early-season woes, according to general manager Brian Cashman.

"We've done the 'CSI: The Bronx' on him a number of different times," Cashman told MLB.com's Bryan Hoch on Thursday. "We've gone through the analytics comparison from when he's flying high to the current low. There are no indicators other than the splitter's not splitting like it usually does, and the command of the fastball is off."

Indeed, after limiting opponents to a .169 average while surrendering just four home runs off his signature splitter in 2016, Tanaka, who will lug an unsightly 6.56 ERA into Friday's start against the Oakland Athletics, has already allowed three homers - and a .511 slugging percentage - off the pitch this year. Though his velocity is actually up almost a full tick from a season ago, shaky fastball command has helped opponents hit .344 with eight homers off Tanaka's four-seamers and sinkers this year, contributing to his career-worst 1.60 WHIP and 2.44 home runs per nine innings.

As such, despite the slight uptick in velocity, concern over his elbow - Tanaka has famously pitched with a partially torn ulnal collateral ligament since 2014 - continues to linger, though the club still sees no need to send him for an MRI, Cashman said.

"From an analytics standpoint and front-office perspective, we can't seem to come up with some reason that would lead us to take that step," Cashman said. "We're not afraid to do it if we felt that was necessary, but we're not going to do something that appears to be unnecessary."